makefile

name	makefile
description	Use when creating Makefiles for process lifecycle management with PID tracking, logging, and status monitoring. Triggers on: 'use makefile mode', 'makefile', 'create makefile', 'process management', 'background jobs', 'start/stop services'. Full access mode - can create/modify Makefiles.
allowed-tools	["Read","Edit","Write","Bash","Grep","Glob"]

Makefile Mode

Create and manage Makefiles optimized for AI agent interaction and process lifecycle management.

Core Philosophy

"Start clean. Stop clean. Log everything. Know your state."

Principles:

• AI-agent first: Outputs readable programmatically (no interactive prompts)
• Background by default: Services run detached; read logs, don't spawn terminals
• Comprehensive logging: All output to files at .logs/ - nothing lost
• Process hygiene: Clean starts, clean stops, no orphan processes
• Adaptable patterns: Works for any service topology

Pre-Implementation Discovery

Before creating a Makefile, determine:

Service Topology

• What services exist? (backend, frontend, workers, etc.)
• Do any services depend on others? (start order)
• Are there external dependencies? (databases, emulators, etc.)

Startup Requirements

• What commands start each service?
• What environment variables are needed?
• What ports are used? (must be unique per-service)
• Any initialization steps? (migrations, seeds, etc.)

Testing & Quality

• What test commands exist? (unit, integration, e2e)
• What prerequisites for tests? (docker, emulators, etc.)
• What linting/formatting tools? (eslint, ruff, mypy, etc.)

Project Context

• Language/framework? (affects conventions)
• Development vs Production behavior?
• Team conventions? (existing practices to preserve)

Makefile Architecture

Standard structure (in order):

# 1. Configuration Variables
# 2. Directory Setup
# 3. Service Lifecycle Targets (run-*, stop-*)
# 4. Combined Operations (run, stop, restart)
# 5. Testing & Quality (test, lint)
# 6. Utility Targets (logs, status, help)
# 7. .PHONY declarations

Core Patterns Library

A. Starting a Service (Background with PID Tracking)

run-backend:
	@mkdir -p .pids .logs
	@if lsof -ti:$(BACKEND_PORT) > /dev/null 2>&1; then \
		echo "❌ Backend already running on port $(BACKEND_PORT)"; \
		exit 1; \
	fi
	@echo "🚀 Starting backend on port $(BACKEND_PORT)..."
	@nohup $(BACKEND_CMD) > .logs/backend.log 2>&1 & echo $$! > .pids/backend.pid
	@echo "✅ Backend started (PID: $$(cat .pids/backend.pid))"

B. Stopping a Service (Process Group Cleanup)

stop-backend:
	@if [ -f .pids/backend.pid ]; then \
		PID=$$(cat .pids/backend.pid); \
		if ps -p $$PID > /dev/null 2>&1; then \
			echo "🛑 Stopping backend (PID: $$PID)..."; \
			kill -TERM -- -$$PID 2>/dev/null || kill $$PID; \
			rm .pids/backend.pid; \
			echo "✅ Backend stopped"; \
		else \
			echo "⚠️  Backend process not found, cleaning up PID file"; \
			rm .pids/backend.pid; \
		fi \
	else \
		echo "ℹ️  Backend not running"; \
	fi

C. Status Checking

status:
	@echo "📊 Service Status:"
	@echo ""
	@for service in backend frontend; do \
		if [ -f .pids/$$service.pid ]; then \
			PID=$$(cat .pids/$$service.pid); \
			if ps -p $$PID > /dev/null 2>&1; then \
				echo "✅ $$service: running (PID: $$PID)"; \
			else \
				echo "❌ $$service: stopped (stale PID file)"; \
			fi \
		else \
			echo "⚪ $$service: not running"; \
		fi; \
	done

D. Log Tailing

logs:
	@if [ -f .logs/backend.log ] || [ -f .logs/frontend.log ]; then \
		tail -n 50 .logs/*.log 2>/dev/null; \
	else \
		echo "No logs found"; \
	fi

logs-follow:
	@tail -f .logs/*.log 2>/dev/null

E. Combined Operations

run: run-backend run-frontend
stop: stop-frontend stop-backend  # Reverse order for clean shutdown
restart: stop run

F. Testing with Prerequisites

test: test-setup
	@echo "🧪 Running tests..."
	@$(TEST_CMD)

test-setup:
	@if [ -n "$(DOCKER_COMPOSE_FILE)" ] && [ -f "$(DOCKER_COMPOSE_FILE)" ]; then \
		docker-compose -f $(DOCKER_COMPOSE_FILE) up -d; \
	fi

G. Help Target (Self-Documenting)

.DEFAULT_GOAL := help

help:
	@echo "Available targets:"
	@echo ""
	@echo "  make run              Start all services"
	@echo "  make stop             Stop all services"
	@echo "  make restart          Restart all services"
	@echo "  make status           Show service status"
	@echo "  make logs             Show recent logs"
	@echo "  make logs-follow      Follow logs in real-time"
	@echo "  make test             Run all tests"
	@echo "  make lint             Run linters and formatters"
	@echo ""
	@echo "Individual services:"
	@echo "  make run-backend      Start backend only"
	@echo "  make run-frontend     Start frontend only"
	@echo "  make stop-backend     Stop backend only"
	@echo "  make stop-frontend    Stop frontend only"

Adaptation Patterns

Scenario	Adaptation
Multiple backends	Use suffix naming: run-api, run-worker, etc.
Database migrations	Add migrate target, make run-backend depend on it
Emulators	Treat like any other service with PID tracking
Docker Compose	Wrap docker-compose commands, track container IDs
Monorepo	Use subdirectory variables: cd $(API_DIR) && ...
Multiple test types	Separate targets: test-unit, test-integration, test-e2e
Watch modes	Use separate watch targets, don't mix with regular run

Best Practices Checklist

Before completing a Makefile, verify:

• All targets are .PHONY (or appropriately not)
• Port numbers are configurable via variables
• Unique ports per service (no conflicts)
• All logs go to .logs/ directory
• All PIDs go to .pids/ directory
• Process group killing (handles child processes)
• Port conflict detection before start
• Human-readable output (colors/emojis)
• help target is default (listed first or .DEFAULT_GOAL)
• Variables use := (simple expansion)
• Error messages are clear and actionable
• Status command shows actual state
• Clean shutdown on stop (SIGTERM first)
• Idempotent operations (safe to run twice)

Common Issues & Solutions

Problem	Solution
PID file exists but process dead	Check ps -p $PID before using PID file
Child processes survive parent kill	Use kill -TERM -- -$PID (process group)
Port already in use	Check with lsof -ti:$PORT before start
Logs interleaved/unreadable	Separate log files per service
Service starts but immediately exits	Redirect stderr: 2>&1, check .logs/
Make variables not evaluated	Use := not =, check $$ vs $
Colors don't show in logs	Use unbuffer or configure service for TTY
Can't stop service (permission)	Run make with same user that started it

Implementation Workflow

Creating a New Makefile

1. Discovery: Ask questions (see Discovery section)
2. Configuration: Set up variables (ports, commands, paths)
3. Core services: Implement run/stop for each service
4. Combined ops: Add run/stop/restart for all services
5. Utilities: Add status, logs, help
6. Testing: Add test targets with prerequisites
7. Quality: Add lint/format targets
8. Validation: Test each target, verify idempotency
9. Documentation: Ensure help is complete and accurate

Amending an Existing Makefile

1. Read current Makefile: Understand existing structure
2. Identify gaps: Compare against best practices checklist
3. Plan changes: Determine what to add/modify
4. Preserve conventions: Keep existing naming/style
5. Incremental changes: Add features one at a time
6. Test each change: Verify nothing breaks
7. Update help: Reflect new targets

Complete Template

A minimal working template for a full-stack app:

# =============================================================================
# Configuration
# =============================================================================
BACKEND_PORT := 3001
FRONTEND_PORT := 3000
BACKEND_CMD := npm run dev --prefix backend
FRONTEND_CMD := npm run dev --prefix frontend
TEST_CMD := npm test

# =============================================================================
# Directory Setup
# =============================================================================
$(shell mkdir -p .pids .logs)

# =============================================================================
# Service Lifecycle
# =============================================================================
run-backend:
	@if lsof -ti:$(BACKEND_PORT) > /dev/null 2>&1; then \
		echo "❌ Backend already running on port $(BACKEND_PORT)"; \
		exit 1; \
	fi
	@echo "🚀 Starting backend on port $(BACKEND_PORT)..."
	@nohup $(BACKEND_CMD) > .logs/backend.log 2>&1 & echo $$! > .pids/backend.pid
	@echo "✅ Backend started (PID: $$(cat .pids/backend.pid))"

run-frontend:
	@if lsof -ti:$(FRONTEND_PORT) > /dev/null 2>&1; then \
		echo "❌ Frontend already running on port $(FRONTEND_PORT)"; \
		exit 1; \
	fi
	@echo "🚀 Starting frontend on port $(FRONTEND_PORT)..."
	@nohup $(FRONTEND_CMD) > .logs/frontend.log 2>&1 & echo $$! > .pids/frontend.pid
	@echo "✅ Frontend started (PID: $$(cat .pids/frontend.pid))"

stop-backend:
	@if [ -f .pids/backend.pid ]; then \
		PID=$$(cat .pids/backend.pid); \
		if ps -p $$PID > /dev/null 2>&1; then \
			echo "🛑 Stopping backend (PID: $$PID)..."; \
			kill -TERM -- -$$PID 2>/dev/null || kill $$PID; \
			rm .pids/backend.pid; \
			echo "✅ Backend stopped"; \
		else \
			echo "⚠️  Backend not found, cleaning up PID file"; \
			rm .pids/backend.pid; \
		fi \
	else \
		echo "ℹ️  Backend not running"; \
	fi

stop-frontend:
	@if [ -f .pids/frontend.pid ]; then \
		PID=$$(cat .pids/frontend.pid); \
		if ps -p $$PID > /dev/null 2>&1; then \
			echo "🛑 Stopping frontend (PID: $$PID)..."; \
			kill -TERM -- -$$PID 2>/dev/null || kill $$PID; \
			rm .pids/frontend.pid; \
			echo "✅ Frontend stopped"; \
		else \
			echo "⚠️  Frontend not found, cleaning up PID file"; \
			rm .pids/frontend.pid; \
		fi \
	else \
		echo "ℹ️  Frontend not running"; \
	fi

# =============================================================================
# Combined Operations
# =============================================================================
run: run-backend run-frontend
stop: stop-frontend stop-backend
restart: stop run

# =============================================================================
# Testing & Quality
# =============================================================================
test:
	@echo "🧪 Running tests..."
	@$(TEST_CMD)

lint:
	@echo "🔍 Running linters..."
	@npm run lint 2>&1 || true

# =============================================================================
# Utilities
# =============================================================================
status:
	@echo "📊 Service Status:"
	@echo ""
	@for service in backend frontend; do \
		if [ -f .pids/$$service.pid ]; then \
			PID=$$(cat .pids/$$service.pid); \
			if ps -p $$PID > /dev/null 2>&1; then \
				echo "✅ $$service: running (PID: $$PID)"; \
			else \
				echo "❌ $$service: stopped (stale PID file)"; \
			fi \
		else \
			echo "⚪ $$service: not running"; \
		fi; \
	done

logs:
	@tail -n 50 .logs/*.log 2>/dev/null || echo "No logs found"

logs-follow:
	@tail -f .logs/*.log 2>/dev/null

clean:
	@rm -rf .pids .logs
	@echo "🧹 Cleaned up PID and log files"

# =============================================================================
# Help
# =============================================================================
.DEFAULT_GOAL := help

help:
	@echo "Available targets:"
	@echo ""
	@echo "  make run           Start all services"
	@echo "  make stop          Stop all services"
	@echo "  make restart       Restart all services"
	@echo "  make status        Show service status"
	@echo "  make logs          Show recent logs (last 50 lines)"
	@echo "  make logs-follow   Follow logs in real-time"
	@echo "  make test          Run tests"
	@echo "  make lint          Run linters"
	@echo "  make clean         Remove PID and log files"
	@echo ""
	@echo "Individual services:"
	@echo "  make run-backend   Start backend only"
	@echo "  make run-frontend  Start frontend only"
	@echo "  make stop-backend  Stop backend only"
	@echo "  make stop-frontend Stop frontend only"

# =============================================================================
# .PHONY
# =============================================================================
.PHONY: run run-backend run-frontend stop stop-backend stop-frontend \
        restart status logs logs-follow test lint clean help

Gitignore Additions

Remind users to add these to .gitignore:

.pids/
.logs/